For this purpose, lactoferrin (Lf), a cationic iron-binding glycoprotein, able to chelate at high affinity (KD w10/20 M) two ferric ions per molecule (30), is emerging as an important regulator of systemic iron homeostasis, able to cure ID and IDA. Lf is synthesized by exocrine glands and neutrophils in infection and inflammation sites. In humans, free iron does not exceed 10-18 M to avoid precipitation, microbial growth and formation of reactive oxygen species. Lf in tissues and secretions and transferrin in blood assure that iron was bound and scarcely available as free-ion.